Feather and down are all good natural heat-retaining materials. Feather has a flat shape with parallel barbs grown on quills in rows. Down has a shape liking cloud and down can be sorted as down-feather and semi-plume. The down feather has a fluffy structure with little shaft or no shaft. The semi-plume has a fluffy structure too, but it has well formed shaft. For these characters, the feather and down cannot be sorted as fiber. Using common technology, we can separate barb-fibers of the feather or down-branch-fibers of the down or semi-plume from their quill or shaft to get separated barb-fibers or down-branch-fibers. The barb fiber has a same structure as the down-branch-fiber but is coarser than the down-branch-fiber. The barb-fiber and down-branch-fiber both are defined as down branch fiber thereafter. Since down branch fiber has very tiny barbules and hooks distributing equally along fiber, the down branch fiber is considered as a kind of unique nature fiber with many merits, for example, soft, light, heat retaining, etc. However, to us common textile technologies such as combing, twisting, draughting to process down branch fibers is very difficult since the down branch fibers are non-crimp, fluffy, and very short, most of them are around 15 mm to 25 mm. This is the main reason that people use feather, barb-branch-fiber and down branch fiber as stuffing materials for making down garment, quilts, ticks and other bedding only.
Chinese Patent Publication Number CN1222591A titled “Down Branch Fiber Fabric and Its Fabricating Method” and Chinese Patent Publication Number CN1293270A titled “Down Shell Fabric” described a kind of spinning method for the mixture of downs or down-branch-fibers with textile fibers.
According to the common knowledge in the down products industry, down is short, soft fluff got from feathers of waterfowls, such as geese, ducks and the like. Down also means a mixture of down, feather, barb-fiber, down branch fiber and other impurity, in which the ration of down must be over the lowest standard stipulated by this industry. The “down” described in the above-mentioned two patent publications is not a kind of material having same structure, it can't be considered as fiber too. Where, the fiber means a kind of natural or synthetic thin filiform textile material only. Downs can't be used as textile materials for spin directly. If spinning the mixture of downs with other textile materials for yarns, it is impossible to get smooth and uniform yarns since down is fluffy and mixed with other impurity, such as feather and barb-fibers. During processing downs will be blown away since downs can't be mixed with other textile fibers as a uniform combination.